| Step | Hyp | Ref | Expression | 
						
							| 1 |  | fproddivf.kph |  |-  F/ k ph | 
						
							| 2 |  | fproddivf.a |  |-  ( ph -> A e. Fin ) | 
						
							| 3 |  | fproddivf.b |  |-  ( ( ph /\ k e. A ) -> B e. CC ) | 
						
							| 4 |  | fproddivf.c |  |-  ( ( ph /\ k e. A ) -> C e. CC ) | 
						
							| 5 |  | fproddivf.ne0 |  |-  ( ( ph /\ k e. A ) -> C =/= 0 ) | 
						
							| 6 |  | nfcv |  |-  F/_ j ( B / C ) | 
						
							| 7 |  | nfcsb1v |  |-  F/_ k [_ j / k ]_ B | 
						
							| 8 |  | nfcv |  |-  F/_ k / | 
						
							| 9 |  | nfcsb1v |  |-  F/_ k [_ j / k ]_ C | 
						
							| 10 | 7 8 9 | nfov |  |-  F/_ k ( [_ j / k ]_ B / [_ j / k ]_ C ) | 
						
							| 11 |  | csbeq1a |  |-  ( k = j -> B = [_ j / k ]_ B ) | 
						
							| 12 |  | csbeq1a |  |-  ( k = j -> C = [_ j / k ]_ C ) | 
						
							| 13 | 11 12 | oveq12d |  |-  ( k = j -> ( B / C ) = ( [_ j / k ]_ B / [_ j / k ]_ C ) ) | 
						
							| 14 | 6 10 13 | cbvprodi |  |-  prod_ k e. A ( B / C ) = prod_ j e. A ( [_ j / k ]_ B / [_ j / k ]_ C ) | 
						
							| 15 | 14 | a1i |  |-  ( ph -> prod_ k e. A ( B / C ) = prod_ j e. A ( [_ j / k ]_ B / [_ j / k ]_ C ) ) | 
						
							| 16 |  | nfvd |  |-  ( ph -> F/ k j e. A ) | 
						
							| 17 | 1 16 | nfan1 |  |-  F/ k ( ph /\ j e. A ) | 
						
							| 18 | 7 | nfel1 |  |-  F/ k [_ j / k ]_ B e. CC | 
						
							| 19 | 17 18 | nfim |  |-  F/ k ( ( ph /\ j e. A ) -> [_ j / k ]_ B e. CC ) | 
						
							| 20 |  | eleq1w |  |-  ( k = j -> ( k e. A <-> j e. A ) ) | 
						
							| 21 | 20 | anbi2d |  |-  ( k = j -> ( ( ph /\ k e. A ) <-> ( ph /\ j e. A ) ) ) | 
						
							| 22 | 11 | eleq1d |  |-  ( k = j -> ( B e. CC <-> [_ j / k ]_ B e. CC ) ) | 
						
							| 23 | 21 22 | imbi12d |  |-  ( k = j -> ( ( ( ph /\ k e. A ) -> B e. CC ) <-> ( ( ph /\ j e. A ) -> [_ j / k ]_ B e. CC ) ) ) | 
						
							| 24 | 19 23 3 | chvarfv |  |-  ( ( ph /\ j e. A ) -> [_ j / k ]_ B e. CC ) | 
						
							| 25 | 9 | nfel1 |  |-  F/ k [_ j / k ]_ C e. CC | 
						
							| 26 | 17 25 | nfim |  |-  F/ k ( ( ph /\ j e. A ) -> [_ j / k ]_ C e. CC ) | 
						
							| 27 | 12 | eleq1d |  |-  ( k = j -> ( C e. CC <-> [_ j / k ]_ C e. CC ) ) | 
						
							| 28 | 21 27 | imbi12d |  |-  ( k = j -> ( ( ( ph /\ k e. A ) -> C e. CC ) <-> ( ( ph /\ j e. A ) -> [_ j / k ]_ C e. CC ) ) ) | 
						
							| 29 | 26 28 4 | chvarfv |  |-  ( ( ph /\ j e. A ) -> [_ j / k ]_ C e. CC ) | 
						
							| 30 |  | nfcv |  |-  F/_ k 0 | 
						
							| 31 | 9 30 | nfne |  |-  F/ k [_ j / k ]_ C =/= 0 | 
						
							| 32 | 17 31 | nfim |  |-  F/ k ( ( ph /\ j e. A ) -> [_ j / k ]_ C =/= 0 ) | 
						
							| 33 | 12 | neeq1d |  |-  ( k = j -> ( C =/= 0 <-> [_ j / k ]_ C =/= 0 ) ) | 
						
							| 34 | 21 33 | imbi12d |  |-  ( k = j -> ( ( ( ph /\ k e. A ) -> C =/= 0 ) <-> ( ( ph /\ j e. A ) -> [_ j / k ]_ C =/= 0 ) ) ) | 
						
							| 35 | 32 34 5 | chvarfv |  |-  ( ( ph /\ j e. A ) -> [_ j / k ]_ C =/= 0 ) | 
						
							| 36 | 2 24 29 35 | fproddiv |  |-  ( ph -> prod_ j e. A ( [_ j / k ]_ B / [_ j / k ]_ C ) = ( prod_ j e. A [_ j / k ]_ B / prod_ j e. A [_ j / k ]_ C ) ) | 
						
							| 37 |  | nfcv |  |-  F/_ j B | 
						
							| 38 | 37 7 11 | cbvprodi |  |-  prod_ k e. A B = prod_ j e. A [_ j / k ]_ B | 
						
							| 39 | 38 | eqcomi |  |-  prod_ j e. A [_ j / k ]_ B = prod_ k e. A B | 
						
							| 40 | 39 | a1i |  |-  ( ph -> prod_ j e. A [_ j / k ]_ B = prod_ k e. A B ) | 
						
							| 41 |  | nfcv |  |-  F/_ j C | 
						
							| 42 | 12 | equcoms |  |-  ( j = k -> C = [_ j / k ]_ C ) | 
						
							| 43 | 42 | eqcomd |  |-  ( j = k -> [_ j / k ]_ C = C ) | 
						
							| 44 | 9 41 43 | cbvprodi |  |-  prod_ j e. A [_ j / k ]_ C = prod_ k e. A C | 
						
							| 45 | 44 | a1i |  |-  ( ph -> prod_ j e. A [_ j / k ]_ C = prod_ k e. A C ) | 
						
							| 46 | 40 45 | oveq12d |  |-  ( ph -> ( prod_ j e. A [_ j / k ]_ B / prod_ j e. A [_ j / k ]_ C ) = ( prod_ k e. A B / prod_ k e. A C ) ) | 
						
							| 47 | 15 36 46 | 3eqtrd |  |-  ( ph -> prod_ k e. A ( B / C ) = ( prod_ k e. A B / prod_ k e. A C ) ) |